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Anna Erickson - One of the best experts on this subject based on the ideXlab platform.
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Polysiloxane scintillators for neutron and gamma-ray pulse shape discrimination
Hard X-Ray Gamma-Ray and Neutron Detector Physics XXII, 2020Co-Authors: Allison Lim, Jonathan Arrue, Paul B. Rose, Alan Sellinger, Anna EricksonAbstract:Plastic scintillators offer a cost-effective and scalable option for detection of special nuclear materials. Traditional plastic scintillators are based on thermoplastics such as poly(Vinyl Toluene) (PVT) and polystyrene. When over-doped with select fluorescent molecules, PVT and polystyrene scintillators are capable of distinguishing between neutrons and gamma ray via pulse shape discrimination (PSD). While this formulation has been extensively studied and commercialized, the resulting scintillators are restricted to applications involving rigid thermoplastics. In order to achieve flexible and elastomeric properties, a new class of elastomer scintillators based on polysiloxanes has been explored. This work details elastomeric polysiloxane scintillators based on a commercial resin and a commercial primary dopant, 2,5-diphenyloxazole (PPO) and a synthesized dopant, 9,9-dimethyl-2-phenyl fluorene (PhF). PPO-polysiloxane scintillators showed PSD capabilities surpassing commercial thermoplastic analogues at low concentrations of PPO (FoM 1.33 ± 0.03 at 450 keVee for 5wt% PPO). PhF-polysiloxane scintillators were also capable of PSD, comparable to the commercial sample, but notably had a high light yield, of 144% EJ-299-33. This work serves as a proof of concept that polysiloxane scintillators can be capable of good PSD and high light yield at low dopant loadings.
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Polysiloxane Scintillators for Efficient Neutron andGamma-Ray Pulse Shape Discrimination
ACS Applied Polymer Materials, 2020Co-Authors: Allison Lim, Jonathan Arrue, Paul B. Rose, Alan Sellinger, Anna EricksonAbstract:Plastic scintillators based on thermoplastics, such as polystyrene and poly(Vinyl Toluene) (PVT), are capable of neutron and γ radiation detection via pulse shape discrimination (PSD) when overdope...
Allison Lim - One of the best experts on this subject based on the ideXlab platform.
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Polysiloxane scintillators for neutron and gamma-ray pulse shape discrimination
Hard X-Ray Gamma-Ray and Neutron Detector Physics XXII, 2020Co-Authors: Allison Lim, Jonathan Arrue, Paul B. Rose, Alan Sellinger, Anna EricksonAbstract:Plastic scintillators offer a cost-effective and scalable option for detection of special nuclear materials. Traditional plastic scintillators are based on thermoplastics such as poly(Vinyl Toluene) (PVT) and polystyrene. When over-doped with select fluorescent molecules, PVT and polystyrene scintillators are capable of distinguishing between neutrons and gamma ray via pulse shape discrimination (PSD). While this formulation has been extensively studied and commercialized, the resulting scintillators are restricted to applications involving rigid thermoplastics. In order to achieve flexible and elastomeric properties, a new class of elastomer scintillators based on polysiloxanes has been explored. This work details elastomeric polysiloxane scintillators based on a commercial resin and a commercial primary dopant, 2,5-diphenyloxazole (PPO) and a synthesized dopant, 9,9-dimethyl-2-phenyl fluorene (PhF). PPO-polysiloxane scintillators showed PSD capabilities surpassing commercial thermoplastic analogues at low concentrations of PPO (FoM 1.33 ± 0.03 at 450 keVee for 5wt% PPO). PhF-polysiloxane scintillators were also capable of PSD, comparable to the commercial sample, but notably had a high light yield, of 144% EJ-299-33. This work serves as a proof of concept that polysiloxane scintillators can be capable of good PSD and high light yield at low dopant loadings.
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Polysiloxane Scintillators for Efficient Neutron andGamma-Ray Pulse Shape Discrimination
ACS Applied Polymer Materials, 2020Co-Authors: Allison Lim, Jonathan Arrue, Paul B. Rose, Alan Sellinger, Anna EricksonAbstract:Plastic scintillators based on thermoplastics, such as polystyrene and poly(Vinyl Toluene) (PVT), are capable of neutron and γ radiation detection via pulse shape discrimination (PSD) when overdope...
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Methacrylate based cross-linkers for improved thermomechanical properties and retention of radiation detection response in plastic scintillators
Nuclear Instruments and Methods in Physics Research Section A: Accelerators Spectrometers Detectors and Associated Equipment, 2018Co-Authors: Adam Mahl, Allison Lim, Joseph Latta, Henok A. Yemam, Uwe Greife, Alan SellingerAbstract:Abstract Pulse shape discrimination (PSD) is an important method that can efficiently sort and separate neutron and gamma radiation signals. PSD is currently achieved in plastic scintillators by over-doping poly(Vinyl Toluene) (PVT) matrices with fluorescent molecules. Meaningful separation of the signals requires addition of >20 wt% 2,5-diphenyloxazole (PPO) fluor in PVT. At these concentrations PPO acts as a plasticizer, negatively affecting the physical properties of the final plastic such as hardness, machinability, and thermomechanical stability. This work addresses these issues by implementing a cost-effective solution using cross-linking chemistry via commercially available bisphenol A dimethacrylate (BPA-DM), and a synthesized fluorinated analogue. Both improve the physical properties of over-doped PPO based plastic scintillators without degrading the measured light yield or PSD and Figure of Merit (FoM). In addition, the fluorinated analogue appears to enhance the hydrophobicity of the surface of the plastic scintillators, which may improve the scintillators’ resistance to water diffusion and subsequent radiation response degradation. The new formulations improve the feasibility of widely deploying long lifetime PSD capable plastic scintillators in large area coverage assemblies.
Alan Sellinger - One of the best experts on this subject based on the ideXlab platform.
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Polysiloxane scintillators for neutron and gamma-ray pulse shape discrimination
Hard X-Ray Gamma-Ray and Neutron Detector Physics XXII, 2020Co-Authors: Allison Lim, Jonathan Arrue, Paul B. Rose, Alan Sellinger, Anna EricksonAbstract:Plastic scintillators offer a cost-effective and scalable option for detection of special nuclear materials. Traditional plastic scintillators are based on thermoplastics such as poly(Vinyl Toluene) (PVT) and polystyrene. When over-doped with select fluorescent molecules, PVT and polystyrene scintillators are capable of distinguishing between neutrons and gamma ray via pulse shape discrimination (PSD). While this formulation has been extensively studied and commercialized, the resulting scintillators are restricted to applications involving rigid thermoplastics. In order to achieve flexible and elastomeric properties, a new class of elastomer scintillators based on polysiloxanes has been explored. This work details elastomeric polysiloxane scintillators based on a commercial resin and a commercial primary dopant, 2,5-diphenyloxazole (PPO) and a synthesized dopant, 9,9-dimethyl-2-phenyl fluorene (PhF). PPO-polysiloxane scintillators showed PSD capabilities surpassing commercial thermoplastic analogues at low concentrations of PPO (FoM 1.33 ± 0.03 at 450 keVee for 5wt% PPO). PhF-polysiloxane scintillators were also capable of PSD, comparable to the commercial sample, but notably had a high light yield, of 144% EJ-299-33. This work serves as a proof of concept that polysiloxane scintillators can be capable of good PSD and high light yield at low dopant loadings.
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Polysiloxane Scintillators for Efficient Neutron andGamma-Ray Pulse Shape Discrimination
ACS Applied Polymer Materials, 2020Co-Authors: Allison Lim, Jonathan Arrue, Paul B. Rose, Alan Sellinger, Anna EricksonAbstract:Plastic scintillators based on thermoplastics, such as polystyrene and poly(Vinyl Toluene) (PVT), are capable of neutron and γ radiation detection via pulse shape discrimination (PSD) when overdope...
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Methacrylate based cross-linkers for improved thermomechanical properties and retention of radiation detection response in plastic scintillators
Nuclear Instruments and Methods in Physics Research Section A: Accelerators Spectrometers Detectors and Associated Equipment, 2018Co-Authors: Adam Mahl, Allison Lim, Joseph Latta, Henok A. Yemam, Uwe Greife, Alan SellingerAbstract:Abstract Pulse shape discrimination (PSD) is an important method that can efficiently sort and separate neutron and gamma radiation signals. PSD is currently achieved in plastic scintillators by over-doping poly(Vinyl Toluene) (PVT) matrices with fluorescent molecules. Meaningful separation of the signals requires addition of >20 wt% 2,5-diphenyloxazole (PPO) fluor in PVT. At these concentrations PPO acts as a plasticizer, negatively affecting the physical properties of the final plastic such as hardness, machinability, and thermomechanical stability. This work addresses these issues by implementing a cost-effective solution using cross-linking chemistry via commercially available bisphenol A dimethacrylate (BPA-DM), and a synthesized fluorinated analogue. Both improve the physical properties of over-doped PPO based plastic scintillators without degrading the measured light yield or PSD and Figure of Merit (FoM). In addition, the fluorinated analogue appears to enhance the hydrophobicity of the surface of the plastic scintillators, which may improve the scintillators’ resistance to water diffusion and subsequent radiation response degradation. The new formulations improve the feasibility of widely deploying long lifetime PSD capable plastic scintillators in large area coverage assemblies.
Tibor Jacob Hajagos - One of the best experts on this subject based on the ideXlab platform.
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Plastic Scintillators for Pulse Shape Discrimination of Particle Types in Radiation Detection
2017Co-Authors: Tibor Jacob HajagosAbstract:Organic scintillators have a long history in the field of radiation detection, dating back to some of the earliest studies of organic photophysics and optoelectronic properties. In particular, plastics have come to dominate the commercial market for organic scintillators, due to their low cost and ease of use and manufacturing, and more notably in spite of their poorer performance in many metrics. While there has been decades of active research since their inception, little progress has been made to improve upon the now well established compositions of commercial plastics, a notable exception being the recent development of plastic scintillators capable of pulse shape discrimination (PSD) of n/γ radiation, which is of particular interest among governments and industry for the detection of illicit nuclear material and weapons. In recent years, much attention has been paid towards the study of luminescent organic materials, in particular due to the invention and widespread adoption of organic light emitting diode (OLED) based electronic devices, and the knowledge and lessons that have been fundamental to such fields have recently begun to be adopted by the organic scintilator community. In this work, new approaches to the design of both plastic scintillator components, and of the materials as a whole, are described, with particular emphasis paid towards the design and synthesis of small molecule scintillating dyes that are specifically tailored towards the development of PSD-capable plastic scintilators. In the first of these approaches, the design and synthesis of a highly soluble and polymerizable derivative of 9,10-diphenylanthracene is described, and the properties of plastic scintilators fabricated from this dye when copolymerized with poly(Vinyl Toluene) were investigated. This particular approach was used to demonstrate a proof-of-concept of PSD in highly loaded plastics stabilized through copolymerization of the primary dye, a strategy conceived to address the particular shortcomings of the current generation of PSD plastics. The second general approach investigated is the application of the phenomenon of thermally activated delayed fluorescence (TADF) — most notably a key innovation among the latest developments in OLED technologies — to the enhancement of the performance of organic sicntillators. Several key observations about the potential and efficacy of TADF dyes as novel organic scintillators were made, including a demonstration of the profound effects the the TADF phenomenon can have on scintillation properties. These findings suggest that it is quite possible that TADF dyes could eventually enable an entirely new generation of high performance organic scintillators, and PSD-capable plastics in particular.
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Applications of fluorene moiety containing polymers for improved scintillation light yield
Nuclear Instruments and Methods in Physics Research Section A: Accelerators Spectrometers Detectors and Associated Equipment, 2017Co-Authors: David Kishpaugh, Tibor Jacob Hajagos, Chao Liu, Qi Chen, Qibing PeiAbstract:Abstract A terfluorene compound, designed and synthesized for its photophysical and polymerizable properties, was employed as a host material in polymer scintillators to achieve a 31% increase in light yield versus a commercial standard viewed with a Silicon Photomultilier. Monomers of the compound were mixed with a solubility promoting Vinyl Toluene and either a commercial or custom designed fluor containing fluorene moiety structures. Fluors were chosen with overlapping energy levels to promote resonance energy transfer from the host material and improve light emission. The mixture was cured via bulk polymerization into cylindrical polymer monoliths which were coupled to either a photomultiplier tube or silicon photomultiplier to measure the scintillation light yield upon exposure to Cs-137 gamma. Samples emitted at longer wavelengths than commercial blue scintillators such as EJ-212 but outperformed this standard when accounting for the variability of photomultiplier tube sensitivity.
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Partial ligand exchange as a critical approach to the synthesis of transparent ytterbium fluoride–polymer nanocomposite monoliths for gamma ray scintillation
Journal of Materials Chemistry C, 2016Co-Authors: Yunxia Jin, David Kishpaugh, Tibor Jacob Hajagos, Chao Liu, Qi Chen, Yi Chen, Qibing PeiAbstract:Partial ligand exchange is reported to be an effective approach to the synthesis of transparent bulk-size ytterbium fluoride–polyVinyl Toluene (PVT) nanocomposites containing a high loading of YbF3 nanoparticles. A bifunctional compound, bis[2-(methacryloyloxy)ethyl] phosphate (BMEP), is introduced to partially replace the oleic acid (OA) ligand on the surface of YbF3 nanoparticles (NPs). The remaining OA helps retain a good dispersion of the nanoparticles in monomer Vinyl Toluene, while grafted BMEP enables the copolymerization of the nanoparticles with the polymer matrix. As a result, bulk transparent YbF3/PVT nanocomposites with 1 mm thickness have been synthesized containing up to 63 wt% of YbF3 nanoparticles (80 wt% if including the weight of the organic ligands and 47 wt% of the net Yb atoms) coupled with a transmission as high as ∼80%. Transmission electron micrographs show a uniform dispersion of the nanoparticles in the polymer matrix due to covalent bonding of the nanoparticles onto the polymer matrix via the BMEP ligand molecules, which overcomes the exclusion of the nanoparticles during the polymer chain growth. A monolith scintillator based on the transparent nanocomposite containing dissolved fluor compounds produces scintillation emission peaked at 416 nm with high light yield under 662 keV gamma ray irradiation.
Paul B. Rose - One of the best experts on this subject based on the ideXlab platform.
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Polysiloxane scintillators for neutron and gamma-ray pulse shape discrimination
Hard X-Ray Gamma-Ray and Neutron Detector Physics XXII, 2020Co-Authors: Allison Lim, Jonathan Arrue, Paul B. Rose, Alan Sellinger, Anna EricksonAbstract:Plastic scintillators offer a cost-effective and scalable option for detection of special nuclear materials. Traditional plastic scintillators are based on thermoplastics such as poly(Vinyl Toluene) (PVT) and polystyrene. When over-doped with select fluorescent molecules, PVT and polystyrene scintillators are capable of distinguishing between neutrons and gamma ray via pulse shape discrimination (PSD). While this formulation has been extensively studied and commercialized, the resulting scintillators are restricted to applications involving rigid thermoplastics. In order to achieve flexible and elastomeric properties, a new class of elastomer scintillators based on polysiloxanes has been explored. This work details elastomeric polysiloxane scintillators based on a commercial resin and a commercial primary dopant, 2,5-diphenyloxazole (PPO) and a synthesized dopant, 9,9-dimethyl-2-phenyl fluorene (PhF). PPO-polysiloxane scintillators showed PSD capabilities surpassing commercial thermoplastic analogues at low concentrations of PPO (FoM 1.33 ± 0.03 at 450 keVee for 5wt% PPO). PhF-polysiloxane scintillators were also capable of PSD, comparable to the commercial sample, but notably had a high light yield, of 144% EJ-299-33. This work serves as a proof of concept that polysiloxane scintillators can be capable of good PSD and high light yield at low dopant loadings.
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Polysiloxane Scintillators for Efficient Neutron andGamma-Ray Pulse Shape Discrimination
ACS Applied Polymer Materials, 2020Co-Authors: Allison Lim, Jonathan Arrue, Paul B. Rose, Alan Sellinger, Anna EricksonAbstract:Plastic scintillators based on thermoplastics, such as polystyrene and poly(Vinyl Toluene) (PVT), are capable of neutron and γ radiation detection via pulse shape discrimination (PSD) when overdope...